Oracle skipper James Spithill (left) chats with Team Korea's Peter Burling, 21, the youngest skipper in the fleet.

Photo: Brant Ward, The Chronicle

Oracle skipper James Spithill (left) chats with Team Korea's Peter...

Image 2 of 3

Skipper James Spithill (left) waves to the crowd after Oracle Team USA Spithill won at the America's Cup World Series in August.

Photo: Beck Diefenbach, Special To The Chronicle

Skipper James Spithill (left) waves to the crowd after Oracle Team...

Image 3 of 3

(l to r) Murray Jones, Shannon Falcone, Kinley Fowler and Skipper, Russell Coutts, on Wednesday August 15, 2012, take a shuttle boat to do a crew change, as the Oracle Team USA practices in preparation for the America's Cup World Series races on San Francisco Bay, Calif.

A little more than five weeks have passed since Jimmy Spithill's Oracle Team USA boat won the first America's Cup World Series regatta in San Francisco by a single point. Another round begins Wednesday, with some new wrinkles.

For one thing, the course has moved about 100 meters to the east. For another, most of the racing will take place after 4 p.m. because of the Fleet Week air-show schedule.

"I think it's going to be harder racing in the fact that (the breeze) might be a little lighter and trickier," Terry Hutchinson, skipper of Artemis Racing White, said. "It's our best opportunity, being later in the day, to get good breezes. The winds start to shut down at the end of the day as the sun goes down."

Unlike the August regatta, the second round will have a strong ebb tide, which might cause the helmsmen to steer farther away from shore.

The course has "moved down and a little offshore," said Chris Draper, who guided Luna Rossa Piranha to a close second-place finish in August. "It's a little bit more toward Alcatraz. It makes it a little harder to get out of the current."

Fans are expected to turn out in droves as the sailing takes turns with the air shows in what should be much warmer weather than the chill the spectators endured in August.

"We have huge expectations for massive crowds that have never really been seen before in sailing to be here on Marina Green watching our event," regatta director Iain Murray said.

They'll see new people at the helms of some of the 11 wingsail catamarans. Nathan Outteridge, whose Team Korea took third in the first round, is now guiding Sweden's Artemis Racing Red. Team CEO Paul Cayard, a San Francisco sailing legend, takes over as tactician for Outteridge.

Peter Burling, 21, a silver medalist in the 49er class in the London Olympics, becomes the youngest skipper in the fleet with Team Korea. Spain's Iker Martinez, a two-time Olympic medalist in the 49er, takes his turn at the helm of Italy's Luna Rossa Swordfish, and Loick Peyron shifts back to the helm of France's Energy Team.

Burling, a tall, soft-spoken New Zealander, said he's not awed by the prospect of competing, with only about five days of practice time, against the best sailors in the world.

"I always seem to be pretty young in the things that I do, so I don't get too overwhelmed or wound up about things," he said. "I'm just looking forward to going out and mixing it up on the racecourse."

Martinez has not sailed a multihull until now, but he said, "I think many things are transferable from 49er to the AC45. It's a fast boat, and especially the format of the races is similar ... with a lot of boats rounding the marks together."

Just how lighter winds will affect the racing is anybody's guess.

"Reading the wind correctly will be more of a factor in this regatta than it was in the last one," August match-racing champion Russell Coutts of Oracle Team USA said. "The calm patches will be exaggerated. If one side of the course has more wind, the differences will be magnified. It's going to be more varied, mixing up the results. It's hard to see somebody dominating this."

For Spithill and the rest of the Oracle team, most of the attention since the last round has been on the 72-foot catamaran that will compete in next year's America's Cup Final. British sailing legend Ben Ainslie is part of that team, although he's sailing for J.P. Morgan BAR in the World Series.

"Personally, I'd love to see all three of us (including Ainslie) on the podium," Spithill said.

Ghost ship

It was the case of the runaway catamaran.

The AC45 of France's Energy Team, which opens match-race competition Wednesday in the America's Cup World Series, broke its mooring at Pier 30-32 Saturday night and drifted into San Francisco Bay before being secured at Treasure Island.

The boat sustained only minor damage and will be ready to race in the regatta, which runs through Sunday.

"Thankfully, it was a very calm night, and the boat was returned to us without sustaining serious damage," regatta director Iain Murray said on the America's Cup website. "We're grateful for the way this ended and for the help of a Good Samaritan at Treasure Island who spotted the boat and secured it before handing it back to us."

Energy Team has offered a guest-racer spot to the Good Samaritan, Todd Tholke. He is set to race with the crew Wednesday.